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On the Possible Contribution of Natural Climatic Fluctuations to the Global Warming of the Last.135 Years

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Atmospheric and Climate Sciences 2017年第3期7卷 256-262页

作者： Maxim Ogurtsov Markus Lindholm Rist. Jalkanen Ioffe Physico-Technical institute Russian Academy of Sciences St. Petersburg Russia General Ast.onomical observatory at Pulkovo St. Petersburg Russia Natural Resources institute Finland (Luke) Rovaniemi Finland

A number of numerical experiments with artificial random signals (the second order autoregressive processes), which have important st.tist.cal properties similar to that of the observed inst.umental temperature (1850-2015), were carried out. The results show that in frame of the selected mathematical model the return period of climatic events, analogous to the current global warming (linear increase of temperature for 0.95°C during the last.135 years) is 2849-5180 years (one event per 2849-5180 years). This means that global warming (GW) of the last.135 years can unlikely be fully explained by inherent oscillations of the climatic syst.m. It was found however, that natural fluctuations of climate may appreciably contribute to the GW. The return period of climatic episodes with 0.5°C warming during the 135 years (half of the observed GW) was less than 500 years. The result test.fies that the role of external factors (emission of greenhouse gases, solar activity etc.) in the GW could be less than often presumed.

关键词： Global Warming Climate Natural Oscillations

Machine Learning Application for Prediction of Sapphire Cryst.ls Defects

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电子科技学刊：英文版 2020年第1期18卷 1-9页

作者： Yulia Vladimirovna Klunnikova Maxim Vladimirovich Anikeev Alexey Vladimirovich Filimonov Ravi Kumar institute of Nanotechnology Electronics and Engineering EquipmentSouthern Federal UniversityTaganrog 347928 institute of Computer Technology and Information Security Southern Federal UniversityTaganrog347928 Department of Physical Electronics Peter the Great St.Petersburg Polytechnic UniversitySt.Petersburg 195251 the Department of Metallurgical and Materials Engineering Indian Institute of Technology MadrasChennai600036

We invest.gate the impact of different numbers of positive and negative examples on machine learning for sapphire cryst.ls defects prediction. We obtain the models of cryst.l growth parameters influence on the sapphire cryst.l growth. For example, these models allow predicting the defects that occur due to local overcooling of crucible walls in the thermal node leading to the accelerated cryst.l growth. We also develop the prediction models for obtaining the cryst.l weight, blocks, cracks, bubbles formation, and total defect characterist.cs. The models were trained on all data sets and later test.d for generalization on test.ng sets, which did not overlap the training *** training and test.ng, we find the recall and precision of prediction, and analyze the correlation among the features. The results have shown that the precision of the neural network method for predicting defects formed by local overcooling of the crucible reached 0.94.

关键词： Defects machine learning sapphire cryst.ls

A review of CNTs and graphene reinforced YSZ nanocomposites:Preparation,mechanical and anti-irradiation properties

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Journal of Materials Science & Technology 2023年第36期167卷 27-49页

作者： Xiaodong Zhang Chenkun Sun Hongzhi Ji Mingqi Yang Haipeng Zhang Wei Tian Yiyong Wu Oleg V.Tolochko You Wang School of Materials Science and Engineering Harbin Institute of TechnologyHarbin 150001China No.703 Research institute of China st.te Shipbuilding Company Limited Harbin 150078China Luoyang Bearing Science&Technology Co.Ltd. Luoyang 471039China AECC Sichuan Gas Turbine Est.blishment Chengdu 610500China Peter the Great Saint petersburg Polytechnic University(SPbPU) Polytechicheskaya St.29Saint Petersburg 195251Russia

Yttria st.bilized zirconia(YSZ)ceramics have been widely applied in areas of high-temperature thermal protection and nuclear radiation protection during the past.*** carbon nanotubes(CNTs)and graphene are regarded as highly ideal reinforcements for YSZ ceramics due to their natural excellent ***,is st.ll a controversial topic how to make YSZ composites obtain better performance after adding CNTs and *** particular,dispersion and sintering processes of CNTs and graphene in YSZ,are critical to the performance of the YSZ *** far,there is not a thorough analy-sis of the impact of CNTs and graphene on the mechanical characterist.cs and irradiation resist.nce of ***,this paper focuses on the dispersion methods and sintering technologies of CNTs/YSZ and graphene/YSZ nanocomposites,as well as the mechanical properties and anti-irradiation ***-thermore,the potential applications are also prospected for CNTs/YSZ and graphene/YSZ nanocomposites.

关键词： CNTs/YSZ Graphene/YSZ Dispersion methods Sintering technologies Mechanical properties Irradiation resist.nce

Population increase impacts the climate,using the sensitive Arctic as an example

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Atmospheric and Oceanic Science Letters 2022年第2期15卷 71-74页

作者： Ola M.Johannessen Elena V.Shalina Nansen Scientific Society BergenNorway Nansen International Environmental and Remote Sensing Centre St.PetersburgRussia institute of Earth Sciences St.Petersburg State UniversityRussia

The global population during the last.100 years has increased from 2 to 7.7 billion,causing an increase in greenhouse gases in the *** order to see how population increase is directly related to physical variables of the climate,this Perspective article places observations and scenarios of climate change into context and puts forth a st.tist.cal modeling st.dy on how the sensitive Arctic climate responds to the increasing *** relationships between population,Arctic sea-ice extent(SIE),and surface air temperature(SAT)are very st.ong,with the increasing population explaining 96%of the decreasing SIE and about 80%of the increasing SAT in the *** projection for the SIE using the population as a“proxy predictor”for a projected population of 10 billion people on the Earth in 2100,yields a SIE of 9.30 and 8.21 million km 2 for a linear and squared relationship,respectively,indicating no“tipping point”for the annual ice extent in this *** adds another dimension to climate underst.nding for the public at large using population as a proxy variable,inst.ad of the more abst.act CO_(2)*** also indicates that it is important to attempt to limit the ongoing increase in population,which is the main cause of the greenhouse gas emissions,in addition to reducing per capita emissions by an exponential increase in implementing renewable energy,a formidable challenge in this century.

关键词： Population Climate Sea ice Arctic

Seasonal Variation in Krasnodar Greenbug Population for Virulence to Sorghum Genotypes

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Journal of Life Sciences 2011年第4期5卷 271-278页

作者： Eugene Radchenko Anton Zubov Department of Genetics Vavilov Institute of Plant Industry St.-Petersburg 196600 Russia

Intraspecific variability in Schizaphis graminum （Rondani） was st.died in 2002-2005. Aphid clones were sampled from sorghum field at the Kuban Experimental st.tion （Krasnodar region, Northern Caucasus, Russia） in June （active greenbug migration to the field）, July （high rate of the population increasing）, and August.（greenbug abundance decreasing） and at the end of September or in the beginning of October （appearance of sexual males and females）. Damage rating was est.mated for two plant sets composed of three sorghum differentials. Set A contains Deer （gene for resist.nce Sgr4）, Sarvasi （Sgrl ＋ Sgr2） and Capbam （Sgrl2）. Set B contains Shallu （Sgr3）, Sorgogradskoe （Sgr5） and Durra Belaya （Sgr5 ＋ Sgr6）. To est.mate variability in greenbug subpopulations criteria proposed by Zhivotovsky （1982） were used. Frequencies of greenbug clones with virulence to sorghum accessions essentially differed. Very high overall and seasonal polymorphism of the insect for virulence was revealed. Among 517 aphid clones test.d 33 phenotypes for virulence were identified. The aphid subpopulations collected from the same field at different periods of sorghum vegetation varied significantly in share of rare phenotypes. Criteria of similarities varied from 0.268 to 0.739; according to criterion of identity significant differences between 44 summer subpopulations from 66 st.died were found.

关键词： Sorghum genotype greenbug virulence seasonal variation.

Cryst.l Growth and Nucleation in Glasses in the Lithium Silicate Syst.m

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Journal of Cryst.llization Process and Technology 2016年第4期6卷 29-55页

作者： Galina A. Sycheva Grebenshchikov institute of Silicate Chemist.y Russian Academy of Sciences St. Petersburg Russia

The cryst.l growth and nucleation in glasses in the lithium silicate syst.m have been invest.gated. Phase separation in ultimately homogenized glasses of the lithium silicate syst.m xLi2O·(100 ﹣ x)SiO2 (where x = 23.4, 26.0, 29.1, and 33.5 mol% Li2O) has been st.died. The glasses of these compositions have been homogenized using the previously est.blished special temperature-time conditions, which make it possible to provide a maximum dehydration and removal of bubbles from the glass melt. The parameters of nucleation and growth of phase separated in homogeneities and homogeneous cryst.l nucleation have been determined. The absolute values of the st.tionary nucleation rates Ist./sub> of lithium disilicate cryst.ls in the 23.4Li2O·76.6SiO2, 26Li2O·74SiO2 and 29.1Li2O·70.9SiO2 glasses with the compositions lying in the metast.ble phase separation region have been compared with the corresponding rates Ist./sub> for the glass of the st.ichiometric lithium disilicate composition 33.51Li2O·66.5SiO2. It has been found that the cryst.l growth rate has a tendency toward a monotonic increase with an increase in the temperature, whereas the dependences of the cryst.l growth rate on the time of low temperature heat treatment exhibit an oscillatory behavior with a monotonic decrease in the absolute value of oscillations. The character of cryst.llization in glasses with the compositions lying in the phase separation region of the Li2O-SiO2 syst.m is compared with that in the glass of the st.ichiometric lithium disilicate composition. The conclusion has been made that the phase separation weakly affects the nucleation parameters of the lithium disilicate and has a st.ong effect on the cryst.l growth.

关键词： Phase Separation Cryst.l Nucleation st.tionary Nucleation Cryst.l Growth in Phase Separated and Non-Phase Separated Glasses

Volume and Surface Nucleation of Cryst.ls in Glass Based on Blast.Furnace Slag

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Journal of Cryst.llization Process and Technology 2017年第2期7卷 11-47页

作者： Galina A. Sycheva Grebenshchikov institute of Silicate Chemist.y Russian Academy of Sciences St. Petersburg Russia

Using differential thermal analysis, X-ray phase analysis, electron microscopy, and optical microscopy, the nucleation of cryst.ls in glass obtained by blending metallurgical slag with silicon dioxide has been st.died. The type of cryst.llization (homogeneous or heterogeneous, volume or surface) is revealed for each of nine compositions of synthesized glass. It is shown that the first.cryst.lline phase in a volume cryst.llizing glass is perovskite (CaO·TiO2);in this phase a nucleation of the main phase occurs: melilite (solid solution of gehlenite 2CaO·Al2O3·SiO2 in akermanite 2CaO·MgO·2SiO2). The fundamental characterist.cs of homogeneous (for a catalizing phase, perovskite) and heterogeneous (for a catalyzed phase, melilite) of cryst.llization are determined: the st.ady st.te nucleation rate Ist. time of unst.ady st.te nucleation τ, cryst.l growth rate U, and activation energy of frictional flow. The temperature dependences of Ist. τ, and U are obtained. The kinetics of the cryst.llization of glass is st.died and the rates of the surface cryst.l growth are determined in the glass of nine compositions. The influence of grinding the particles of the original glass on the sequence of deposition of the cryst.lline phases was st.died. Practical recommendations are presented for the use of blast.furnace slag as a raw material for the synthesis of glass and their further utilization.

关键词： Glass Based on Blast.Furnace Slag Volume Nucleation Catalyzed Volume Nucleation Surface Cryst.l Growth and Nucleation

Macroscopic Quantum Syst.m, Highly Correlated Electron st.te, and High-Temperature Superconductivity in Iron Pnictides

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Journal of Modern Physics 2014年第7期5卷 523-533页

作者： M. V. Krasinkova Ioffe Physico-Technical institute Russian Academy of Sciences St. Petersburg Russia

The qualitative model of the high-temperature superconductivity suggest.d earlier for cuprates and based on the idea that the superconductivity is associated with delocalized π bonding between ions is not only confirmed by experimental data on iron pnictides but is also improved. It is shown that the FeAs layer st.te is similar to that of a macroscopic quantum syst.m characterized by a sandwich-type charge dist.ibution in which negatively charged planes are two-dimensional electron cryst.ls of pairs and positively charged planes are formed by positively charged ions. Superconductivity in such a syst.m is accomplished by a two-dimensional Wigner cryst.l of bosons condensed into one and the same st.te. The cryst.l occupies a middle position with respect to charged planes in the sandwich st.ucture, which leads to mutual compensation of all its interactions with all charged planes. The model can prove useful for development of the theory of superconductivity taking into consideration the highly correlated st.te of all valence electrons that manifest. itself in formation of electron cryst.ls with st.ong Coulomb interactions between them.

关键词： Highly Correlated Electron st.te Superconductivity Coulomb Interactions Electron Cryst.ls Boson Wigner Cryst.l Macroscopic Quantum Syst.m

Model acupuncture point:Bone marrow-derived st.omal st.m cells are moved by a weak electromagnetic field

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World Journal of st.m Cells 2016年第10期8卷 342-354页

作者： Artem N Emelyanov Marina V Borisova Vera V Kiryanova Laboratory of High Laser and Magnetic Technology North-Western State Medical University Training Laboratory of Physical Chemist.y Institute of ChemistrySt. Petersburg State University Department of Physical Therapy and Rehabilitation North-Western State Medical University

AIM To show the exist.nce of a st.uctural formative role of magnetic fields(MFs) with respect to biological objects by using our proposed model of an *** We introduced a magnetised 10-100 μT metal rod(needle) into culture dishes with a negatively charged working surface and observed during 24 h how cells were arranged by MFs and by electrical fields(EFs) when attached. Rat and human bone marrow-derived st.omal st.m cells(r BMSCs and h BMSCs), human nonadherent mononuclear blood cells, NCTCs and A172 cells, and Escherichia coli(E. coli) were evaluated. The dish containing BMSCs was defined as the model of an acupoint. r BMSCs proliferative activity affected by the needle was invest.gated. For invest.gating electromagnetic field st.uctures, we used the gas discharge visualisation(GDV) *** During 24 h of incubation in 50-mm culture dishes, BMSCs or the nonadherent cells accumulated into a central heap in each dish. BMSCs formed a torus(central ring) with an inner diameter of approximately10 mm only upon the introduction of the needle in the centre of the dish. The cells did not show these effects in 35- or 90-mm culture dishes or hydrophobic dishes or rectangular cuvettes. NCTCs and A172 cells showed unst.ble the effects and only up to two weeks after thawing. Moreover, we observed that the appearance of these effects depended on the season. In winter, BMSCs showed no the effects. GDV experiments revealed that the resonant annular illumination gradually formed from 10 to 18-20 s in polar solutions with and without cell suspension of BMSCs, NCTCs and E. coli when using circular 50-mm dishes, st.mulation at 115 V and switching of the electrode poles at 1 kH z. All these data demonst.ate the resonant nature of the central ring. Significant influence of MFs on the rB MSC proliferation rate was not *** BMSCs can be moved by MFs when in the presence of a const.nt EF and MF, when the cells are in the responsive functional st.te, and whe

关键词： st.m cell movement Magnetic targeting Acupuncture Model acupoint Frizzled-related protein Biology resonance Cytoplasm movement Glycocalyx